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T Takvorian

Publications and source records attributed to T Takvorian.

32 records · Page 2Linked to original sources

Autologous bone marrow transplantation in the treatment of malignant lymphoma and Hodgkin's disease.

High-dose chemotherapy, both with and without radiotherapy, was pioneered in the treatment of acute leukemia in relapse with allogeneic transplantation, exploiting the steep dose-response curve characteristic of some hematologic neoplasms. Extension to the malignant lymphomas was strengthened by early success in Burkitt's lymphoma and in syngeneic transplantation for lymphoma. The optimal regimen (BACT [carmustine, cytarabine, cyclophosphamide, 6-thioguanine]) and setting are still under investigation for the various grades of lymphomas. The early published experience demonstrated a low ultimate "cure" rate when transplantation was performed in advanced, bulky, and refractory disease. A survey of published reports up to 1986 showed only 16 of 112 long-term, disease-free survivors when autologous bone marrow transplantation (ABMT) was performed in refractory relapse as opposed to 33 of 53 for patients transplanted in second or subsequent remission or in first partial remission. Refractoriness to conventional-dose chemotherapy (no response or progressive disease) cannot be salvaged in the majority of cases. Bone marrow involvement complicates the use of ABMT and may require in vitro elimination with monoclonal antibodies/complement or cytotoxic chemicals. The Dana-Farber Cancer Institute experience shows that the former in vitro treatment does not inhibit bone marrow grafting. When selection criteria for ABMT are applied in drug-sensitive relapse, 50% to 60% long-term, disease-free survival may be expected. Definition of poor prognostic factors in large cell lymphoma may identify patients for ABMT as consolidation of first remission. The issue of marrow purging is unsettled at the present time.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Prolonged disease-free survival after autologous bone marrow transplantation in patients with non-Hodgkin's lymphoma with a poor prognosis.

Despite advances in the primary treatment of non-Hodgkin's lymphoma, relapse is common and treatment after relapse is unsatisfactory. Autologous bone marrow transplantation, although sometimes successful, has generally had disappointing results. We conducted a trial of such transplantation in patients with relapsed non-Hodgkin's lymphoma, using strict criteria in selecting patients; we included only those in whom disease was minimal after conventional treatment (nodal disease less than 2 cm and bone marrow involvement less than or equal to 5 percent on histologic examination) and whose tumor cells expressed the B1 antigen. Forty-nine patients meeting these criteria received cyclophosphamide and whole-body irradiation supported by transplantation of autologous bone marrow that had been treated in vitro with anti-B1 monoclonal antibody and complement. All patients had features of a poor prognosis, including relapse from primary chemotherapy, histologic conversion to more aggressive disease, and extra-nodal dissemination. Thirty-three patients had a history of bone marrow involvement--16 at the time that marrow was obtained. Hematologic and immunologic engraftment was achieved in all patients. Only two treatment-related deaths occurred, from venoocclusive disease of the liver and intracerebral hemorrhage, respectively. Disease-free remission without maintenance therapy has lasted from greater than 2 to greater than 52 months in 34 patients (median follow-up, greater than 11 months). These results are similar to those obtained in patients with advanced, high-grade non-Hodgkin's lymphoma treated with primary combination chemotherapy. This study demonstrates that autologous bone marrow transplantation has tolerable toxicity and high efficacy in a subset of patients who are otherwise incurable but still responsive to cytoreductive therapy. The results suggest a role for such transplantation in the treatment of selected patients with newly diagnosed non-Hodgkin's lymphoma.

B-Lymphocytes↗

Thallium-201 brain tumor imaging: a comparative study with pathologic correlation.

In patients with gliomas who were stable or improving, we noted a disparity between clinical status and computed tomography (CT) brain scan results. To elucidate this finding, 29 patients were sequentially scanned with 2.0 mCi of 201Tl (5-30 min), 20 mCi [99mTc]gluceptate (GH) (3-4 hr) and 7-10 mCi 67Ga (48-72 hr). A total of 198 images were obtained. A set of three scans at a midpoint in follow up was selected for analysis. Seven patients who died had neuropathologic data available; brain sections were reconstructed to match radionuclide views without knowledge of image results. In the seven patients with autopsy data, 201Tl offered the most accurate correlation with viable tumor. Gallium-67 gave similar results in patients not receiving steroids. Technetium-99m GH scans could not allow differentiation between tumor, necrosis, and edema. Similarly, the CT scan could not routinely differentiate between fibrotic, nonfibrotic, necrotic, and neoplastic tissue. In the 22 patients without autopsy data, 201Tl scans commonly showed smaller and more focal abnormal uptake when compared with [99mTc]GH and 67Ga scans. Thallium-201 scans more accurately reflect viable tumor burden than other radionuclide studies of primary brain tumors, are minimally affected by concomitant steroid administration, can be performed immediately following tracer administration, and complement the anatomic data obtained from CT scans.

Adolescent↗

Hematologic engraftment and immune reconstitution posttransplantation with anti-B1 purged autologous bone marrow.

Hematologic engraftment and immune reconstitution were examined in patients who received cyclophosphamide and total body irradiation therapy followed by infusion of autologous bone marrow purged with anti-B1 monoclonal antibody (MoAb) and complement as therapy for non-Hodgkin's lymphoma. Hematologic engraftment was prompt with return of greater than or equal to 0.5 X 10(3)/microL granulocytes and greater than or equal to 2 X 10(4)/microL platelets at a median of 26 and 29 days posttransplant, respectively. Immunologic reconstitution, in contrast, was prolonged. Normal numbers of circulating B cells were consistently noted by five months posttransplant, whereas return of normal immunoglobulin levels in some patients did not occur for one year. Normal numbers of T cells were evident within the first month posttransplant, but a reversed T4:T8 ratio persisted in some patients up to three years. In vitro responses of either B cells to triggers of activation or of T cells to mitogens and antigens were not normal for at least three months posttransplant. Natural killer (NK) cells predominated early after transplant and may demonstrate cytotoxicity against tumor cells. Our studies demonstrate that transplantation with anti-B1 purged autologous bone marrow results in complete hematologic and delayed immunologic engraftment. No significant acute or chronic clinical toxicities have been observed.

Antibodies, Monoclonal↗

Characterization of natural killer cells with antileukemia activity following allogeneic bone marrow transplantation.

To identify cells with potential antileukemia activity following bone marrow transplantation, we have monitored immunologic reconstitution in a patient with acute lymphocytic leukemia in second remission who received intensive chemotherapy and total body irradiation followed by infusion of allogeneic histocompatible marrow. Prior to transplantation, donor bone marrow cells were depleted of T lymphocytes by in vitro treatment with anti-T12 monoclonal antibody and rabbit complement. In the first 3 weeks following bone marrow transplantation, the predominant regenerating mononuclear cell population in peripheral blood exhibited a phenotype characteristic of natural killer (NK) cells. After 4 weeks, T lymphocytes became predominant, but NK cells persisted. Cultured peripheral blood lymphocytes obtained 12 weeks posttransplant were able to display significant cytotoxicity against leukemic blasts that had been cryopreserved at the time of relapse 5 months prior to bone marrow transplantation. To further characterize those cells with antileukemia activity, we used in vitro cloning techniques to identify four monoclonal populations, termed TC12, -48, -50, and -59, with strong antitumor activity. Cytogenetic analysis demonstrated that each clone was of donor origin. Phenotypic characterization showed that the four clones expressed NKH1A but did not express T3, T4, or T8 antigens. Three of the four clones expressed T11/E rosette antigen. Each clone exhibited strong cytotoxicity against genetically unrelated hematopoietic tumor cell lines such as K562, Molt-4, JM, and U937. In addition, we found that these patient clones were similar to cloned NK cells previously derived from normal individuals. Taken together, these results suggest that at least some clones with antileukemia activity following bone marrow transplantation are cells with NK-like function and phenotype. Functional analysis of these cytolytic cells in larger numbers of patients will be necessary to determine the clinical significance of this finding.

Adult↗

Use of highly polymorphic DNA probes for genotypic analysis following bone marrow transplantation.

The use of DNA markers known as restriction fragment length polymorphisms is a sensitive and informative method of distinguishing patient and allogeneic donor cells after bone marrow transplantation. To apply the test, it is necessary in each case to find DNA probes that display patient-specific and donor-specific bands in Southern transfer hybridization. We have isolated a set of 12 cloned DNAs from highly polymorphic loci by which siblings can usually be distinguished. With just four of these probes, we can expect to distinguish the genotypes of the recipient and a sibling donor in more than 99% of cases (except between identical twins). The availability of many highly polymorphic probes also allows selection of an optimal probe for each case, one that can detect both the patient and donor-specific bands in a single hybridization with maximum resolution and sensitivity. We have applied these probes to the analysis of cells from peripheral blood and bone marrow after transplantation and demonstrated their usefulness in confirming engraftment of donor cells or graft rejection, and in detecting mixed lympho-hematopoietic chimerism.

Base Sequence↗

Continuous infusion of high-dose 1-beta-D-arabinofuranosylcytosine: a phase I and pharmacological study.

High doses of 1-beta-D-arabinofuranosylcytosine, administered as a continuous i.v. infusion, were evaluated in a Phase I trial in 14 patients with advanced solid tumors. 1-beta-D-Arabinofuranosylcytosine was given at 250 mg/sq m/h for infusions of 12 to 36 h. The mean steady state 1-beta-D-arabinofuranosylcytosine plasma level was 19.6 microM with a range of 9 to 59 microM. The principal toxicity was myelosuppression. An infusion of 18 h was well tolerated by most patients. A Phase II dose of 250 mg/sq m/h for 24 h can be used if platelet support is available. This dose schedule may be useful in the treatment of hematological disorders or in clinical combinations with DNA-damaging agents in the treatment of solid tumors.

Adult↗

Anti-B1 monoclonal antibody and complement treatment in autologous bone-marrow transplantation for relapsed B-cell non-Hodgkin's lymphoma.

Eight patients with relapsed B-cell non-Hodgkin's lymphoma were treated with intensive chemoradiotherapy and reconstituted with autologous bone marrow rendered free of tumour cells by the B-cell-specific monoclonal antibody anti-B1 and complement. Before the autologous marrow transplantation patients were induced with chemotherapy, radiotherapy, or both, into a minimum disease state with less than 5% bone-marrow involvement with tumour. All patients treated achieved a complete clinical response and had stable haematological engraftment by 8 weeks. No significant acute or chronic toxic effects have occurred. B cells could be detected by 2 months after transplantation and normal immunoglobulin levels were achieved by 6 months. Six of eight patients are disease free in unmaintained remission more than 20, 19, 10, 8, 5, and 3 months after transplantation.

Adult↗

Autologous bone-marrow transplantation: host effects of high-dose BCNU.

Thirty-five patients with solid tumors received 44 courses of bis-chlorethylnitrosourea (BCNU) at doses ranging between 600 and 1,400 mg/m2 with cryopreserved or fresh autologous bone-marrow support. Eight patients treated at 600 mg/m2 received no bone-marrow support for their first course of BCNU. Maximum follow-up was 25 months (median, four months). Myelosuppression was severe and dose related but was less prolonged in the marrow-supported groups (p = 0.01) and was not dose limiting. Myelosuppression-related toxicity of infection and hemorrhage occurred in 21 (47%) of 44 courses of treatment. Pulmonary toxicity occurred in seven of 35 patients; abnormal liver function occurred in 18 of 30 patients greater than one month from treatment; and central nervous system symptoms that may have been drug related occurred in six of 35 patients. There was no renal or cardiac toxicity. Except for myelosuppression, toxicity was not dose related. Treatment-related deaths included four with pulmonary toxicity, two with liver toxicity, sepsis in four, and gastrointestinal tract toxicity in one patient. We conclude that the limiting side effect of high-dose BCNU (greater than or equal to 600 mg/m2) is visceral toxicity; the extent of myelosuppression is shortened by the infusion of bone marrow, whether cryopreserved or fresh; and marked tumor regression can be achieved with high-dose BCNU.

Adult↗

High-dose BCNU with autologous bone marrow rescue for recurrent glioblastoma multiforme.

Eleven patients with recurrent malignant glioma were treated with single high doses of BCNU ranging from 600 to 1400 mg/sq m. To prevent the characteristic late myelosuppression observed after conventional doses of BCNU, autologous bone marrow harvested just before drug treatment was infused 24 to 36 hours after therapy. Higher doses of BCNU causes earlier and more profound myelosuppression; one patient died on pancytopenia, breakdown of the gut epithelium, and Clostridium septicemia 10 days after receiving 1400 mg/sq m of BCNU. All patients experienced transient emesis; four developed transient elevation of hepatic enzymes, two reversible interstitial pulmonary infiltrates, and two who received 1400 mg/sq m BCNU suffered irreversible cortical damage. Eight patients receiving 600 to 1200 mg/sq m demonstrated reconstitution of polymorphonuclear leukocytes an platelets within at least 30 days after treatment. With a follow-up time of up to 19 months, four patients improved, three stabilized, and three deteriorated and died. The median survival time was 7 months. Computerized tomography performed on patients receiving constant corticosteroids showed diminished contrast enhancement and mass effect in eight patients. High-dose BCNU at doses up to 1200 mg/sq m with marrow rescue is a feasible approach to the treatment of patients with glioblastoma.

Adolescent↗